如何使用Maven配置文件和设置示例通过Spring Boot加载环境特定的配置和属性

Question

Read the mongodb user name and password from settings.xml based on profile selection in pom.xml. I am not getting idea how to do. Can any one give example.

I followed reference link

https://examples.javacodegeeks.com/enterprise-java/spring/loading-environment-specific-configurations-properties-spring-using-maven-profiles-xml-settings-file-example/

pom.xml

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">//here showing error


<modelVersion>4.0.0</modelVersion>
<groupId>com.example</groupId>
<artifactId>demo</artifactId>
<packaging>jar</packaging>
<version>1.0</version>
<name>Spring Maven Properties Example Code</name>

<properties>

    <!-- Generic properties -->
    <java.version>1.8</java.version>
    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
    <resource.directory>src/main/resources</resource.directory>

</properties>
<parent>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-parent</artifactId>
    <version>1.5.9.RELEASE</version>

</parent>
<dependencies>

    <dependency>
        <groupId>ch.qos.logback</groupId>
        <artifactId>logback-classic</artifactId>
        <version>1.1.11</version>
        <exclusions>
            <exclusion>
                <groupId>org.slf4j</groupId>
                <artifactId>slf4j-api</artifactId>
            </exclusion>
        </exclusions>
    </dependency>
    <dependency>
        <groupId>org.postgresql</groupId>
        <artifactId>postgresql</artifactId>
    </dependency>
    <dependency>
        <groupId>org.apache.maven.shared</groupId>
        <artifactId>maven-filtering</artifactId>
        <version>1.3</version>
    </dependency>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-thymeleaf</artifactId>
    </dependency>

    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-data-jpa</artifactId>
    </dependency>

    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-data-mongodb</artifactId>
    </dependency>
    <!-- Test Artifacts -->


</dependencies>

<profiles>
    <profile>
        <id>dev</id>
        <!-- Dev Env. Properties -->
        <properties>
            <profile.name>${profile.name}</profile.name>
            <!-- Database Properties -->
            <db.driverClass>${db.driverClass}</db.driverClass>
            <db.connectionURL>${db.connectionURL}</db.connectionURL>
            <db.username>${db.username}</db.username>
            <db.password>${db.password}</db.password>

        </properties>
        <activation>
            <activeByDefault>true</activeByDefault>
        </activation>
    </profile>
    <profile>
        <id>test</id>
        <!-- Test Env. Properties -->
        <properties>
            <profile.name>${profile.name}</profile.name>
            <!-- Database Properties -->
            <db.driverClass>${db.driverClass}</db.driverClass>
            <db.connectionURL>${db.connectionURL}</db.connectionURL>
            <db.username>${db.username}</db.username>
            <db.password>${db.password}</db.password>

        </properties>
    </profile>
    <profile>
        <id>prod</id>
        <!-- Prod Env. Properties -->
        <properties>
            <profile.name>${profile.name}</profile.name>
            <!-- Database Properties -->
            <db.driverClass>${db.driverClass}</db.driverClass>
            <db.connectionURL>${db.connectionURL}</db.connectionURL>
            <db.username>${db.username}</db.username>
            <db.password>${db.password}</db.password>

        </properties>
    </profile>
</profiles>

<build>

    <plugins>
        <plugin>
            <artifactId>maven-compiler-plugin</artifactId>
            <version>3.2</version>
            <configuration>
                <source>${java.version}</source>
                <target>${java.version}</target>
            </configuration>
        </plugin>

        <plugin>
            <groupId>org.apache.maven.plugins</groupId>
            <artifactId>maven-resources-plugin</artifactId>
            <version>2.6</version>
            <configuration>
                <!-- specify UTF-8, ISO-8859-1 or any other file encoding -->
                <encoding>${project.build.sourceEncoding}</encoding>
            </configuration>
        </plugin>
    </plugins>

    <resources>
        <!-- Placeholders that are found from the files located in the configured 
            resource directories are replaced with the property values found from the 
            profile specific configuration file. -->
        <resource>
            <directory>${resource.directory}</directory>
            <filtering>true</filtering>
        </resource>
    </resources>

</build>

application.properites

db.connectionURL=${db.connectionURL}
db.username=${db.username}
db.password=${db.password}

I put the settings.xml file in current project dir. settings.xml

<profiles>
        <profile>
            <id>dev</id>
            <!-- Dev Env. Properties -->
            <properties>
                <profile.name>dev</profile.name>
                <!-- Database Properties -->
                <db.driverClass>com.mysql.jdbc.Driver</db.driverClass>
<db.connectionURL>jdbc:postgresql://localhost:5432/springbootdb</db.connectionURL>
<db.username>postgres</db.username>
<db.password>postgres</db.password>

            </properties>
        </profile>
        </profiles>

MainApplication

public class DemoApplication {

    public static void main(String[] args) {
        SpringApplication.run(DemoApplication.class, args);
    }
}

Here i am testing for postgres weather it is working or not but showing error in pom.xml file here

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"> 

the error is

Project build error: 
Resolving expression: '${db.password}': Detected the following recursive expression cycle in 'db.password': [db.password]

I want to test scenarios for postgres and monngodb.

Help me out..

Answer 1

If you are using Spring Boot, the syntax for Maven filtering is slightly different. You should use @propery@ instead of ${property} . So you should change your application.properties as follows :

db.connectionURL=@db.connectionURL@
db.username=@db.username@
db.password=@db.password@

This blog gives more details